Réaction #2028899

Équation de réaction

n-Butyllithium

trans-4-propylcyclohexanecarboxylic acid chloride

ethyl acetate

diisopropylamine

→

3-oxo-3-(trans-4-propyl-cyclohexyl)-propionic acid ethyl ester

Rendement 91.0%

Solvants

THF

THF

Conditions de réaction

Traitement

1. 1
   Autrewas kept at −40° C.
2. 2
   workup.ADDITIONwere added dropwise
3. 3
   TempératureAfter the reaction mixture had been slowly warmed up to room temperature
4. 4
   Autreit was quenched with a saturated aqueous solution of ammonium chloride
5. 5
   workup.ADDITIONWater (1,000 ml) was then added
6. 6
   Autreto give two layers
7. 7
   ExtractionThe water layer was extracted with toluene (500 ml) three times
8. 8
   Lavagethe combined organic layer was washed with water
9. 9
   Séchagedried over anhydrous magnesium sulfate
10. 10
    workup.DISTILLATIONThe solvent was distilled off under reduced pressure
11. 11
    AutreThe residue was purified by silica gel chromatography (silica gel: 300 g, eluent: toluene)

Mode opératoire

THF (1,000 ml) was added to diisopropylamine (162.9 g) in a reaction vessel under an atmosphere of nitrogen. n-Butyllithium was added dropwise, while the solution was kept at −40° C. or lower, and the stirring was continued for 30 minutes. The solution was cooled at −65° C. or lower, and ethyl acetate (141.9 g) and then a THF (200 ml) solution of trans-4-propylcyclohexanecarboxylic acid chloride (2) (189.9 g) prepared in the first step were added dropwise. After the reaction mixture had been slowly warmed up to room temperature with stirring, it was quenched with a saturated aqueous solution of ammonium chloride. Water (1,000 ml) was then added to give two layers. The water layer was extracted with toluene (500 ml) three times, and the combined organic layer was washed with water and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure. The residue was purified by silica gel chromatography (silica gel: 300 g, eluent: toluene) to give 3-oxo-3-(trans-4-propyl-cyclohexyl)-propionic acid ethyl ester (3) (220 g) in 90% yield.

Source